control of alimentary system

Question 1

what controls the alimentary system?

Answer 1

nerves and hormones

Question 2

which 2 types of nerves control the alimentary system?

Answer 2

somatic and autonomic

Question 3

which 2 types of somatic nerves control the alimentary system?

Answer 3

sensory and motor

Question 4

which 2 types of autonomic nerves control the alimentary system?

Answer 4

parasympathetic and sympathetic

Question 5

give examples of somatic control of the alimentary system

Answer 5

eating, doing toilet, mastication

Question 6

what influence does the sympathetic NS have on the alimentary system?

Answer 6

directs blood away from gut towards essential organs

Question 7

what influence does the parasympathetic NS have on the alimentary system?

Answer 7

kicks in when we rest, stimulates gut motility

Question 8

which hormones control the GIT?

Answer 8

cholrcystokinin (CCK), gastrin, gastric inhibitory peptide (GIP), secretin

Question 9

what is the function of cholecystokinin?

Answer 9

bile sack mover, stimulates production of bile to digest fat

Question 10

where is gastrin produced? and what cells produce it?

Answer 10

produced by G cells in the stomach

Question 11

what is the function of gastrin?

Answer 11

activates parietal cells which produce HCl

Question 12

when is gastro inhibitory peptide (GIP) produced?

Answer 12

in response to insulin regulation

Question 13

which structure releases secretin into the bloodstream?

Answer 13

duodenum

Question 14

what is the function of secretin?

Answer 14

reduces gastrin secretions and neutralises acid coming from the duodenum

Question 15

which type of nervous control is most active at the top (mouth) and bottom (anal canal) of the GIT?

Answer 15

somatic

Question 16

which nervous control is most active at the middle of the GIT?

Answer 16

autonomic

Question 17

At which structures in the GIT do most hormones work?

Answer 17

stomach and small intestine

Question 18

what is the function of the mouth and pharynx?

Answer 18

secretion - saliva

motility - chewing and swallowing

Question 19

secretary control of saliva is completely neural via which nerves?

Answer 19

cranial

Question 20

which two stimuli stimulate saliva production?

Answer 20

chemical and mechanical

Question 21

which chemical stimuli stimulate saliva production?

Answer 21

gustation and olfaction

Question 22

which cranial nerves are responsible for gustation?

Answer 22

CN VII, IX

Question 23

which cranial nerves are responsible for olfaction?

Answer 23

CN I

Question 24

which 2 mechanical stimuli stimulate saliva production?

Answer 24

chewing and psychic

Question 25

which cranial nerve is responsible for chewing?

Answer 25

CN V

Question 26

which salivary stimuli has the greatest strength?

Answer 26

chemical

Question 27

which muscles are involved in chewing?

Answer 27

jaw, facial, and tongue

Question 28

which muscles are involved in swallowing?

Answer 28

jaw, tongue, pharyngeal

Question 29

what does the 'swallowing centre' contain?

Answer 29

brain, nerves and muscles

Question 30

which types of muscle are in the oesophagus?

Answer 30

smooth and skeletal

Question 31

which secretion does the stomach produce?

Answer 31

gastric juice

Question 32

state the 3 phases of gastric secretion

Answer 32

cephalic phase, gastric phase and intestinal hase

Question 33

what stimulates cephalic phase of gastric activity?

Answer 33

mechanical - chewing chemical - taste, smell psychic - visual, emotional

Question 34

what stimulates gastric phase of gastric activity?

Answer 34

mechanical - distension | chemical - food in stomach

Question 35

what stimulates intestinal phase of gastric activity?

Answer 35

mechanical - distension | chemical - acid or protein in duodenum

Question 36

what controls cephalic phase of the gastric cycle?

Answer 36

nerves (long)

Question 37

what controls gastric phase of the gastric cycle?

Answer 37

nerves (long and short) and hormones (gastrin)

Question 38

what controls intestinal phase of the gastric cycle?

Answer 38

nerves (long and short) and hormones (GIP and secretin)

Question 39

describe what happens during cephalic phase of the gastric cycle?

Answer 39

. taste, smell, though or sensation of food sends impulses to medulla oblongota of brain . these impulses cause PNS neutrons via vagus nerves to stimulate secretion of HCl, pepsin and gastrin

Question 40

describe what happens during gastric phase of the gastric cycle?

Answer 40

. food enters and distends stomach, activating PNS reflex via vagus nerves . this reflex results in continued secretion of HCl and pepsin

Question 41

describe what happens during intestinal phase of the gastric cycle?

Answer 41

. chyme enters duodenum, low pH and lipids I'm chyme stimulate PNS neurons in vagal nerves to inhibit gastric secretion, local reflexes that decrease gastric secretion are also stimulated . release of hormones which travel in blood to gastric glands inhibiting their secretion are stimulated

Question 42

what does the small intestine secrete?

Answer 42

intestinal juices (bile, pancreatic juice, chyme)

Question 43

in which way does the small intestine carry out motility?

Answer 43

mixing, segmentation contractions, peristalsis and villus movement

Question 44

what controls the small intestine?

Answer 44

local nerves in response to intra-luminal stimuli (distension)

Question 45

during which stage of gastric activity is most of the pancreatic juice produced?

Answer 45

intestinal phase

Question 46

which hormone is the main stimulator of enzyme-rich pancreatic juice?

Answer 46

CCK

Question 47

which hormone is the main stimulator of bicarbonate-rich pancreatic juice?

Answer 47

secretin

Question 48

where is secretin produced and what triggers its production?

Answer 48

released from duodenum in response to acid

Question 49

what is the function of the bicarbonate in pancreatic juice?

Answer 49

makes pancreatic juice highly alkaline in order to neutralise acid

Question 50

where is CCK produced and what triggers its production?

Answer 50

produced from duodenum in response to fat

Question 51

in what way does the cephalic phase of gastric secretion stimulate the production of bile?

Answer 51

the vagus nerve causes relaxation of the sphincter of oddi (allowing secretions to enter duodenum)

Question 52

in what way does the intestinal phase of gastric secretion stimulate the production of bile?

Answer 52

. CCK is released from duodenum in response to fat/protein, this stimulates contraction of gall bladder and relaxation of sphincter of oddi

Question 53

what secretions does the large intestine and rectum produce?

Answer 53

mucus, water and electrolytes

Question 54

in what way does the large intestine and rectum carry out motility?

Answer 54

mixing, mass movement and defeacation

Question 55

name the 3 extrinsic reflexes of the gastrointestinal tract

Answer 55

long reflexes, gastro-ileac reflex, gastro-colic reflex

Question 56

what is the function of long nerves in the anal canal?

Answer 56

allow us to decide when to go to the toilet

Question 57

what is the function of local nerves in the anal canal?

Answer 57

tell us we need the toilet